Self-assembled monolayer overlying a carbon nanotube substrate

ABSTRACT

One example includes a semiconductor device. The semiconductor device include a carbon nanotube substrate, a self-assembled monolayer, and a gate oxide. The self-assembled monolayer overlies the carbon nanotube substrate and is comprised of molecules each including a tail group, a carbon backbone, and a head group. The gate oxide overlies the self-assembled monolayer, wherein the self-assembled monolayer forms an interface between the carbon nanotube substrate and the gate oxide.

RELATED APPLICATION

This application is a continuation application which claims priorityfrom U.S. patent application Ser. No. 15/340,499, filed 1 Nov. 2016, thesubject matter of which is incorporated herein by reference in itsentirety.

TECHNICAL FIELD

This disclosure relates generally to a semiconductor device, and morespecifically to a self-assembled monolayer overlying a carbon nanotubesubstrate.

BACKGROUND

Carbon nanotubes are the one-dimensional form of graphene. Single wallcarbon nanotubes have the sp2 bonding structure of graphene, rolled intoa single layer, seamless straw. For small diameter tubes, the electronicband structure is effectively one-dimensional, which leads to uniqueelectrical characteristics. A correlation between the density of statesand carrier group velocity can yield a transistor that is intrinsicallylinear, with every step in the gate voltage generating proportionalchange in the drain current. This leads to a potential to significantlyreduce power dissipation.

SUMMARY

One example includes a semiconductor device. The semiconductor deviceincludes a carbon nanotube substrate, a self-assembled monolayer, and agate oxide. The self-assembled monolayer overlies the carbon nanotubesubstrate and is comprised of molecules each including a tail group, acarbon backbone, and a head group. The gate oxide overlies theself-assembled monolayer, wherein the self-assembled monolayer forms aninterface between the carbon nanotube substrate and the gate oxide.

Another example includes a method of forming a semiconductor device. Themethod includes forming a carbon nanotube substrate and forming aself-assembled monolayer from a precursor applied to a surface of thecarbon nanotube substrate, the self-assembled overlying the carbonnanotube substrate and being comprised of molecules each including atail group, a carbon backbone, and a head group. The method furtherincludes forming a gate oxide overlying the self-assembled monolayer,wherein the self-assembled monolayer form an interface between thecarbon nanotube substrate and the gate oxide.

Another example includes another method of forming a semiconductordevice. The method includes applying a precursor to a surface of carbonnanotube substrate, and controlling a hold time of the precursor toprovide a time for the precursor to chemically bond to the carbonnanotube substrate and physically transform into a self-assembledmonolayer overlying the carbon nanotube substrate, the self-assembledmonolayer comprising molecules each including a tail group, a carbonbackbone, and a head group. The method further includes overlying a gateoxide onto the self-assembled monolayer, wherein the self-assembledmonolayer forms an interface between the carbon nanotube substrate andthe gate oxide.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a carbon nanotube semiconductor device.

FIGS. 2A and 2B illustrate an example of a chemical reaction between aprecursor and a tether layer of trimethylaluminum (TMA).

FIG. 3 illustrates an example system for overlaying and aligningmolecules of a self-assembled monolayer of the carbon nanotubesemiconductor device.

FIGS. 4A and 4B illustrate an example hydrophilic surface of siliconoxide and an example hydrophobic surface of a self-assembled monolayer.

FIG. 5 illustrates an example of water contact angle test results forThiol precursor as a function of pulse time.

FIG. 6 illustrates an example of water contact angle test results forThiol precursor as a function of hold time.

FIG. 7 illustrates an example of a method for forming the carbonnanotube semiconductor device.

FIG. 8 illustrates an example of another method for forming the carbonnanotube semiconductor device.

DETAILED DESCRIPTION

This disclosure relates generally to a semiconductor device, and morespecifically to a self-assembled monolayer overlying a carbon nanotubesubstrate that includes at least one carbon nanotube. The example carbonnanotube device may be applied to devices that have high dynamic rangeat low power dissipation. The unique electronic properties of carbonnanotube one-dimensional semiconductors may increase dynamic range ofsuch devices by 10,000×, with no increase in power consumption.

The carbon nanotube device provides for electronics that have low powerdissipation, and high dynamic range. The carbon nanotube device includesan interface layer between carbon nanotubes and a high permittivity(high-k) gate oxide that preserves the good electronic properties of thetubes while enabling good adhesion of the gate oxide, allowing for ahigh-k gate oxide that has low leakage current and high breakdownvoltage. The interface layer protects a substrate of the carbon nanotubedevice from the reactive chemicals used to form the high-k gate oxide.

FIG. 1 illustrates an example of a carbon nanotube semiconductor device100. The carbon nanotube semiconductor device 100 is comprised of acarbon nanotube substrate 110, a self-assembled monolayer (SAM) 120formed on a top surface of the carbon nanotube substrate 110, and a gateoxide 130 formed on a top surface of the SAM 120. For example, the gateoxide 130 can be at least a portion of a gate of a transistor device,such as a Field Effect Transistor (FET).

In the example of FIG. 1, the carbon nanotube substrate 110 isdemonstrated as a bottom layer of the carbon nanotube semiconductordevice 100. The carbon nanotube substrate 110 is comprised of any of avariety of components that include at least one carbon nanotube,chemical mechanical polished (CMP) quartz, thermally oxidized silicon(SiO₂), platinum (Pt), and/or any other component(s) that can be usedwith a carbon nanotube to form a semiconductor device. The carbonnanotube substrate 110, in particular the CMP quartz component,typically includes pinholes and surface traps that form during theformation of the carbon nanotube substrate 110. The SAM 120 overlaysthese types of surface defects to prevent such surface defects frominterfering with the formation and operation of the gate oxide 130.

The SAM 120 is chemically bonded to a top surface of the carbon nanotubesubstrate 110. In an example, the SAM 120 is formed with a thicknessbetween approximately 1 nm and 2 nm. The SAM 120 is comprised of orderedorganic molecules that spontaneously form self-limiting monolayers. Suchmonolayers of the SAM 120 creates homogenous gate oxide overlay overdissimilar surfaces of the carbon nanotube substrate 110. As discussedabove, the carbon nanotube substrate 110 can be comprised of any numberof components, with the gate oxide 130 potentially reacting to thedifferent components of the carbon nanotube substrate 110 in differentways, some being detrimental to the carbon nanotube substrate 110. TheSAM 120 provides a single material with which the gate oxide 130 willreact with during formation thereof, the SAM 120 contacting andproviding a protective film over the carbon nanotube substrate 110,while protecting the components of carbon nanotube substrate 110 (e.g.,carbon nanotube(s), SiO₂, quartz, and platinum) from any reactivechemicals that are used to form the gate oxide 130. The SAM 120 alsoacts as a bridge from the carbon nanotube substrate 110 to the gateoxide 130, substantially mitigating the interface therebetween andsurface traps of the carbon nanotube substrate 110. Such a bridgesubstantially mitigates I-V hysteresis and leakage current between thecarbon nanotube substrate 110 and the gate oxide 130.

The SAM 120 forms an interface between the carbon nanotube substrate 110and the gate oxide 130. Such an interface is formed from a precursorthat is comprised of molecules each having a tail group of atomsattached to a carbon backbone which is attached to a head group ofatoms, discussed in more detail below.

In an example, the carbon nanotube semiconductor device 100 may furtherinclude a molecular tether material 125. Such a tether material 125promotes bonding of the SAM 120 to the top surface of the carbonnanotube substrate 110. Such bonding reduces processing time required toproduce a high quality SAM 120 on substrate materials that can includeSiO₂ and quartz. In an example, the tether material 125 is formed on thesurface of the carbon nanotube substrate 110 from trimethylaluminum(TMA) material, however any tether material 125 may be employed thataids the SAM 120 to tether to the carbon nanotube substrate 110. Surfacehydroxyls on SiO₂ and quartz of the carbon nanotube substrate 110 reactquickly with the TMA, leaving a layer of methyl- and/ordimethly-aluminum, which are then available to react with the precursor,the precursor being one or more chemical compounds that react withand/or decompose on the surface of the carbon nanotube substrate 110 toform the SAM 120. Such application of the tether material 125 to thecarbon nanotube substrate 110 reduces a time and temperature needed toproduce the SAM 120 from the precursor 210.

FIGS. 2A and 2B illustrate an example chemical reaction 200 between aprecursor 210 and a tether material 125, the tether material 125 havingbeen already formed on a surface of the carbon nanotube substrate 110that, as discussed above may include quartz. In the example shown inFIGS. 2A and 2B, the precursor 210 is comprised ofTriethoxy(octyl)silate (ODTS). In other examples, the precursor 210 caninclude Undecanethiol (Thiol) and Trichlorododecylsilane (DTS). Theprecursor 210 includes one or more of the linear formulas, for example,CH₃(CH₂)₉CH₂SH, CH₃(CH₂)₁₀SH, CH₃(CH₂)₁₁SiCl₃, CH₃(CH₂)₇Si(OC₂H₅)₃. ODTSforms a SAM 120 slowly on a quartz surface of the carbon nanotubesubstrate 110. To accelerate SAM 120 layer formation on such a quartzsurface, the tether material 125 is first deposited onto the surface ofthe carbon nanotube substrate 110. Thereafter, the precursor 210 isapplied onto the tether material 125. With such a tether material 125used to form the SAM 120, the SAM 120 may be formed approximately threetimes faster than without use of the tether material 125.

As illustrated in FIG. 2A, an aluminum atom from the tether material 125has a chemical reaction with an oxygen atom of the precursor 210.Multiple such oxygen atoms from the precursor 210 may react withmultiple aluminum atoms of the tether material 125. FIG. 2B illustratesthe tether material 125 after having formed a chemical bond with theprecursor 210. As shown, multipole oxygen atoms from a single precursor210 molecule can form chemical bonds with multiple aluminum atoms of thetether material 125 on the surface of the carbon nanotube substrate 110.In the example of the precursor 210 being ODTS, three oxygen atoms fromthe precursor 210 bond with three aluminum atoms of the tether material125.

FIG. 3 illustrates an example system 300 for overlaying and aligningmolecules of the SAM 120 of the carbon nanotube semiconductor device100. In an example, the system 300 includes an overlay device 310, acontroller 360, and a gate oxide deposition device 370.

The overlay device 310 includes a pressure vessel 315 to pressurize theprecursor 210 prior to being introduced to the carbon nanotube substrate110. The overlay device 310 introduces the pressurized precursor 210 tothe carbon nanotube substrate 110 to overlay the precursor 210 onto thecarbon nanotube substrate 110. The controller 360 controls operation ofthe overlay device 310, controlling a temperature at which the precursor210 is held at during overlay of the SAM 120 on the carbon nanotubesubstrate 110 and controls a hold time that the precursor 210 is allowedto remain on the carbon nanotube substrate 110.

At a time T1, the overlay device 310 overlays the precursor 210 on a topsurface of the carbon nanotube substrate 110. In an example, each of themolecules of the precursor 210 includes a head group 330, a carbonbackbone 340, and a tail group 350. The carbon backbone 340 includescarbon chains that connect the head group 330 to the tail group 350,with a number of such carbon chains being proportional to the density ofthe SAM 120 on the surface of the carbon nanotube substrate 110. Thehead group 330 and the tail group 350 dictate chemistry and formationbehavior of the SAM 120. Initially at time T1, molecules of theprecursor 210 are oriented in random directions. Initially, at time T1the controller 360 instructs the overlay device 310 to release a propercontrolled amount of the precursor 210 to the top surface of the carbonnanotube substrate 110 during SAM 120 formation. In an example, thecontroller 360 instructs the overlay device 310 to set one or more of aninternal pressure of chamber and a temperature of the chamber of theoverlay device 310 during SAM 120 formation. The controller 360 controlsdelivery, via the overlay device 310, of the proper controlled amountthe precursor 210 to the carbon nanotube substrate 110 under vacuum viacontrol of a vapor pressure of the precursor 210 and a pulse duration ofthe overlaying. In an example in which the SAM 120 is formed via AtomicLayer Deposition (ALD), the pulse is a cycle in which the precursor 210reacts with the surface of the carbon nanotube substrate 110 in aself-limiting way, so that the reaction terminates once all reactivesites on the surface of the carbon nanotube substrate 110 are consumed.Multiple such pulses may be used to build the SAM 120 until a uniformthickness is achieved. The controller 360 controls a density of the SAM120 by increasing a number of such pulses and/or increasing a length oftime the SAM 120 is allowed to form on the carbon nanotube substrate110. In an example, the SAM 120 formed with ALD may be overlaid on thecarbon nanotube substrate 110 in approximately thirty minutes. In anexample, the SAM 120 formed with ALD may be overlaid on the carbonnanotube substrate 110 at room temperature, while other overlaytechniques require curing bakes prior to overlay of the gate oxide 130to eliminate out-gassing. As a result of implementing ALD for SAM 120formation, a chamber used to form the SAM 120 is connected to a chamberused to form the gate oxide 130, which eliminates exposure of the carbonnanotube semiconductor device 100 to atmosphere between depositions andwhich maintains control of the interface formed by the SAM 120.Additionally, an amount of precursor 210 applied to a surface of thecarbon nanotube substrate 110 can be better controlled, which allows formore control of a density of the SAM 120 and shorter formation times ofthe SAM 120 compared with formation times that are possible withimmersion and vapor prime.

In an example, the overlay device 310 includes the pressure vessel 315,but depending on the type of overlay being used may also be implementedwithout the pressure vessel 315. Such a pressure vessel 315 pressurizesthe precursor 210 prior to injecting the precursor 210 into the chamberof the overlay device 310 in which the carbon nanotube substrate 110 isloaded for processing. The overlay device 310 utilizes at least one of,for example, spin-on, vapor prime, immersion, ALD, chemical vapor,and/or any other overlay process that allows the SAM 120 to form on thecarbon nanotube substrate 110. In an example, the overlay device 310allows the carbon nanotube substrate 110 to remain under vacuum with noexposure to atmosphere, preventing degradation of the SAM 120 duringformation of the SAM 120.

In an example, the precursor 210 includes molecules with polar endgroups, for example, —OH, —COOH, and —NH2 terminations. Combinations ofSAMs 120 may be used on a single carbon nanotube substrate 110 toprovide multiple functionality for such a carbon nanotube substrate 110,where each of such combinations can address separate performanceimprovements on different areas of the carbon nanotube substrate 110. Inan example, prior to the time T1 in which the overlay device 310 appliesthe precursor 210 on the top surface of the carbon nanotube substrate110, the overlay device 310 can overlay the tether material 125 onto thecarbon nanotube substrate 110 to speed formation of the SAM 120.

At a time T2, molecules of the precursor 210 bond to the top surface ofthe carbon nanotube substrate 110. Such bonding is dictated bychemistry, and therefore are specific for the carbon nanotube substrate110 selected to form the carbon nanotube semiconductor device 100. Thetail group 350 of the precursor 210 bonds to the top surface of thecarbon nanotube substrate 110 including at least one carbon nanotube andany other components of the carbon nanotube substrate 110, leaving thehead group 330 and the carbon backbone 340 free to move about the bondedtail group 350. The head group 330 terminates the growth of the SAM 120and allows the growth of the gate oxide 130 to the SAM 120. The headgroup 330 modifies the surface of the SAM 120 to be more or lesshydrophobic. A hydrophilic SAM 120 provides a consistent growth surfacefor the gate oxide 130 that accelerates nucleation and increasesuniformity of overlaying films on the SAM 120. In an example, thedeposition device 310, under control of the controller 360, pulses thehead group 330 with water and/or oxygen to assist in termination of thehead group 330.

At a time T3, molecules of the precursor 210 align substantiallyvertically on and perpendicular to the top surface of the carbonnanotube substrate 110. Such alignment is dictated by physics withmolecules of the precursor 210 automatically aligning themselves overtime. Ideally, all of the molecules of the precursor 210 align in asubstantially vertical direction to form a dense, well packed SAM 120,with the tail group 350 of such molecules of the precursor 210 forming auniform coating on the top of the carbon nanotube substrate 110.However, less than all of the molecules of the precursor 210 may alignin the vertically on and perpendicular to the top surface of the carbonnanotube substrate 110 to obtain the numerous benefits of the SAM 120.Thus, the overlay device 310, under control of the controller 360, formsthe SAM 120 as an interface onto which the gate oxide 130 can thereafterbe formed. For example, such an interface can withstand ALD up to 120degrees Celsius.

The controller 360 controls an exposure of the carbon nanotube substrate110 to the precursor 210, the exposure being a function of a dose timeand a hold time, the dose time being a time that the carbon nanotubesubstrate 110 is exposed to the precursor 210. The hold time provides atime for the precursor 210 to chemically bond to the carbon nanotubesubstrate 110 and physically transform into the SAM 120. The controller360 controls a pulse length of the precursor 210 during ALD. Thereafter,the controller 360 controls a hold time in which a chamber of theoverlay device 310 is isolated from a pump, allowing the molecules ofthe precursor 210 to diffuse around the chamber and rearrange on thecarbon nanotube substrate 110 to form the SAM 120. In an example, thecontroller 360 tests the surface of the SAM 120 to measure a degree ofhydrophobic behavior of the SAM 120, determining whether the surfacethereof is more or less hydrophobic, discussed in more detail in relatedto FIG. 4B.

At a time T4, the controller 360 controls the gate oxide depositiondevice 370 to overlie the gate oxide 130 on the SAM 120. Thus, overlayof the gate oxide 130 on the SAM 120 eliminates problems discussed aboveassociated with overlay of the gate oxide 130 directly on the carbonnanotube substrate 110.

FIGS. 4A and 4B illustrate an example hydrophilic surface of siliconoxide and an example hydrophobic surface of SAM 120. As shown in FIG.4A, a liquid bead 420 (e.g., water) is placed on a top surface of asilicon oxide substrate 430 that lacks a SAM 120 overlay. Such a liquidbead 420 on the silicon oxide substrate 430 results in the liquid bead420 spreading out across the surface thereof to produce a small (e.g.,less than 70 degrees) water contact angle (WCA) 410. Such a WCA 410provides a measurement of average surface energy on the silicon oxidesubstrate 430, with the silicon oxide substrate 430 having low averagesurface energy and having a hydrophilic surface. In contrast to thesilicon oxide substrate 430 shown in FIG. 4A, FIG. 4B shows a liquidbead 420 that is placed on a top surface of a SAM 120 overlay. Such aliquid bead 420 on the SAM 120 results in the liquid bead 420 forming asphere on the surface thereof to produce a large (e.g., greater than 70degrees) WCA 410. Such a WCA 410 for a liquid bead 420 placed on thesurface of the SAM 120 indicates that the SAM 120 has high averagesurface energy and has a hydrophobic surface. Such a hydrophobic surfaceof the SAM 120 provides an improved surface to which the gate oxide 130is thereafter formed.

FIG. 5 illustrates example WCA 410 test results for Thiol precursor 210as a function of pulse time. For the results shown in FIG. 5, Thiol isdosed in a chamber of the overlay device 310 for various pulse lengths.Thereafter, the chamber is subject to a fixed 600 second “hold” at 60degrees Centigrade, where the chamber of the overlay device 310 isisolated from the pump of the overlay device 310 to allow the Thiolmolecules to diffuse around the chamber and rearrange on the surface ofthe various samples being tested. In the example shown in FIG. 5, thesamples include thermally oxidized silicon (SiO₂), chemical mechanicalpolished (CMP) quartz, and platinum (Pt). Even with a short three seconddose of Thiol, the test results for Pt illustrate that the WCA 410increases approximately 30 degrees versus an uncoated control substrateof Pt, with no change in the WCA 410 for CMP quartz or SiO₂.

FIG. 6 illustrates example WCA 410 test results for Thiol precursor 210as a function of hold time. For the results shown in FIG. 6, Thiol isdosed in a chamber of the overlay device 310 for 20 seconds at 60degrees Centigrade. Thereafter, the chamber of the overlay device 310 isisolated from the pump of the overlay device 310 to allow the Thiolmolecules to diffuse around the chamber and onto the surface of thevarious samples being tested for various hold times. In the exampleshown in FIG. 6, the samples include thermally oxidized silicon (SiO₂),chemical mechanical polished (CMP) quartz, and platinum (Pt). Thiol isshown to quickly produce a WCA 410 change on Pt surfaces, even for shorthold times. Extended exposure of each of the different substrates,thermally oxidized SiO₂, CMP quartz, and Pt, increases the WCA 410 atsimilar rates. Even with a short three second dose of Thiol, the testresults for Pt illustrate that the WCA 410 again increases approximately30 degrees versus an uncoated control substrate of Pt. In contrast tothe test results shown in FIG. 5 based on pulse times, the test resultsof FIG. 6 show that the WCA 410 for each of the different substrates,thermally oxidized SiO₂, CMP quartz, and Pt, increases as hold timesincrease.

In view of the foregoing structural and functional features describedabove, a method in accordance with various aspects of the presentdisclosure will be better appreciated with reference to FIGS. 7 and 8.While, for purposes of simplicity of explanation, the methods of FIGS. 7and 8 are shown and described as executing serially, it is to beunderstood and appreciated that the present disclosure is not limited bythe illustrated order, as some aspects could, in accordance with thepresent disclosure, occur in different orders and/or concurrently withother aspects from that shown and described herein. Moreover, not allillustrated features may be required to implement a method in accordancewith an aspect of the present disclosure. Moreover, for simplicity ofexplanation, the methods of FIGS. 7 and 8 can include additionalfunctional features not discussed, with FIGS. 7 and 8 being describedwith reference to the examples illustrated herein.

FIG. 7 illustrates an example of a method 700 of forming the carbonnanotube semiconductor device 100. At 710, carbon nanotube substrate 110is formed. At 720, the SAM 120 is formed from the precursor 210, the SAM120 overlying the carbon nanotube substrate 110. The SAM 120 is formedwhen the tail group 350 chemically bonds to the top surface of thecarbon nanotube substrate 110, and the carbon backbones 340 and the headgroups 330 of molecules of the precursor 210 line up substantially inparallel with respect to each other and substantially perpendicular tothe carbon nanotube substrate 110. At 730, the gate oxide 130 is formedoverlying the SAM 120. The controller 360 controls processes needed toform the SAM 120 on the surface of the carbon nanotube substrate 110 andcontrol the processes needed to overlie the gate oxide 130 onto the SAM120. Thus, the SAM 120 forms an interface between the carbon nanotubesubstrate 110 and the gate oxide 130.

FIG. 8 illustrates another example of a method 800 of forming the carbonnanotube semiconductor device 100. At 810, the precursor 210 is appliedto the carbon nanotube substrate 110. The controller 360 controls theoverlay device 310 to apply the proper controlled amount of theprecursor 210 to the top surface of the carbon nanotube substrate 110.At 820, a hold time of the precursor 210 is controlled to provide a timefor the precursor 210 to chemically bond to the carbon nanotubesubstrate 110 and physically transform into the SAM 120 overlying thecarbon nanotube substrate 110. The controller 360 selects an optimalhold time based on the particular SAM 120 selected, the material makeupof the carbon nanotube substrate 110, for example whether the carbonnanotube substrate 110 includes CMP quartz, thermally oxidized SiO₂,and/or platinum. At 830, the gate oxide 130 is overlaid onto the SAM120. The controller 360 controls processes needed to form the SAM 120 onthe surface of the carbon nanotube substrate 110 and control theprocesses needed to overlie the gate oxide 130 onto the SAM 120. Thus,the SAM 120 forms an interface between the carbon nanotube substrate 110and the gate oxide 130.

What have been described above are examples of the disclosure. It is, ofcourse, not possible to describe every conceivable combination ofcomponents or method for purposes of describing the disclosure, but oneof ordinary skill in the art will recognize that many furthercombinations and permutations of the disclosure are possible.Accordingly, the disclosure is intended to embrace all such alterations,modifications, and variations that fall within the scope of thisapplication, including the appended claims.

What is claimed is:
 1. A semiconductor device, comprising: a carbonnanotube substrate; a self-assembled monolayer overlying the carbonnanotube substrate, the self-assembled monolayer providing a hydrophobicsurface over the carbon nanotube substrate; and a gate oxide overlyingthe self-assembled monolayer, wherein the self-assembled monolayer formsan interface between the carbon nanotube substrate and the gate oxide.2. The semiconductor device of claim 1, wherein the tail group ischemically bonded to a surface of the carbon nanotube substrate to formthe self-assembled monolayer.
 3. The semiconductor device of claim 1,wherein the self-assembled monolayer comprises molecules of a precursorthat are applied to a surface of the carbon nanotube substrate, suchthat the molecules of the precursor are aligned substantiallyperpendicular with respect to the carbon nanotube substrate andsubstantially in parallel with respect to each other.
 4. Thesemiconductor device of claim 1, further comprising a tether materialthat tethers the self-assembled monolayer to the carbon nanotubesubstrate.
 5. The semiconductor device of claim 1, wherein theself-assembled monolayer is formed from a precursor comprising at leastone of Undecanethiol (Thiol), Trichlorododecylsilane (DTS) andTriethoxy(octyl)silane (ODTS).
 6. The semiconductor device of claim 1,wherein semiconductor device is a Field Effect Transistor (FET).
 7. Thesemiconductor device of claim 1, wherein the carbon nanotube substratefurther comprises at least one of chemical mechanical polished quartz,thermally oxidized silicon, and platinum.
 8. A method, comprising:forming a carbon nanotube substrate; overlaying a precursor on a surfaceof the carbon nanotube substrate to form a self-assembled monolayer, theself-assembled monolayer providing a hydrophobic surface over the carbonnanotube substrate; and overlaying a gate oxide on the self-assembledmonolayer, wherein the self-assembled monolayer forms an interfacebetween the carbon nanotube substrate and the gate oxide.
 9. The methodof claim 8, wherein overlaying the precursor comprises overlaying theprecursor to the carbon nanotube substrate via at least one of spin-on,vapor prime, immersion, and Atomic Layer Deposition (ALD).
 10. Themethod of claim 8, wherein forming the carbon nanotube substratecomprises forming the carbon nanotube substrates from at least one ofchemical mechanical polished quartz, thermally oxidized silicon, andplatinum.
 11. The method of claim 8, further comprising controlling ahold time to provide a time for alignment of molecules of the precursorto be substantially perpendicular with respect to the carbon nanotubesubstrate and substantially in parallel with respect to each other, toform the self-assembled monolayer.
 12. The method of claim 8, furthercomprising overlaying a tether material layer on the carbon nanotubesubstrate, wherein overlaying the precursor comprises overlaying theprecursor on a surface of the tether material layer to form theself-assembled monolayer.
 13. The method of claim 8, wherein theprecursor comprises at least one of Undecanethiol (Thiol),Trichlorododecylsilane (DTS) and Triethoxy(octyl)silane (ODTS).
 14. Themethod of claim 8, further comprising delivering the precursor to thecarbon nanotube substrate under vacuum via control of a vapor pressureof the precursor and a pulse duration of the precursor.
 15. A method,comprising: applying a precursor to a surface of a carbon nanotubesubstrate; controlling a hold time of the precursor to provide a timefor the precursor to chemically bond to the carbon nanotube substrateand physically transform into a self-assembled monolayer overlying thecarbon nanotube substrate, the self-assembled monolayer providing ahydrophobic surface over the carbon nanotube substrate; and overlaying agate oxide onto the self-assembled monolayer, wherein the self-assembledmonolayer forms an interface between the carbon nanotube substrate andthe gate oxide.
 16. The method of claim 15, wherein the precursor isapplied to the carbon nanotube substrate via at least one of spin-on,vapor prime, immersion, and Atomic Layer Deposition (ALD).
 17. Themethod of claim 15, wherein forming the carbon nanotube substratecomprises forming the carbon nanotube substrates from at least one ofchemical mechanical polished quartz, thermally oxidized silicon, andplatinum.
 18. The method of claim 15, wherein controlling the hold timecomprises controlling the hold time to control an alignment of moleculesof the precursor to be substantially perpendicular with respect to thecarbon nanotube substrate and substantially in parallel with respect toeach other, to form the self-assembled monolayer.
 19. The method ofclaim 15, further comprising overlaying a tether material layer on thecarbon nanotube substrate, wherein overlaying the precursor comprisesoverlaying the precursor on a surface of the tether material layer toform the self-assembled monolayer.
 20. The method of claim 15, whereinthe precursor comprises at least one of Undecanethiol (Thiol),Trichlorododecylsilane (DTS) and Triethoxy(octyl)silane (ODTS).